/**
 * Copyright (c) 2011-2014, hubin (243194995@qq.com).
 *
 * Licensed under the Apache License, Version 2.0 (the "License"); you may not
 * use this file except in compliance with the License. You may obtain a copy of
 * the License at
 *
 * http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */
package wang.leq.sso.common.util;

import java.awt.Color;
import java.awt.Font;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.RenderingHints;
import java.awt.geom.AffineTransform;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileOutputStream;
import java.io.IOException;
import java.io.OutputStream;
import java.util.Arrays;
import java.util.Random;

import javax.imageio.ImageIO;

/**
 * 验证码工具类
 * <p>
 * @author   hubin
 * @Date	 2015-2-21 	 
 */
public class VerifyCodeUtils {

	/***
	 * 使用到Algerian字体，系统里没有的话需要安装字体，
	 * 去掉了0,1,4,i,l,o几个容易混淆的字符
	 */
	private static final String VERIFY_CODES = "abcdefghjkmnpqrstuvwxyz2356789";

	private static Random random = new Random();


	/**
	 * 生成随机验证码文件,并返回验证码值
	 * @param w
	 * @param h
	 * @param outputFile
	 * @param verifySize
	 * @return
	 * @throws IOException
	 */
	public static String outputVerifyImage( int w, int h, File outputFile, int verifySize ) throws IOException {
		String verifyCode = generateVerifyCode(verifySize);
		outputImage(w, h, outputFile, verifyCode);
		return verifyCode;
	}


	/**
	 * 输出随机验证码图片流,并返回验证码值
	 * @param w
	 * @param h
	 * @param os
	 * @param verifySize
	 * @return
	 * @throws IOException
	 */
	public static String outputVerifyImage( int w, int h, OutputStream os, int verifySize ) throws IOException {
		String verifyCode = generateVerifyCode(verifySize);
		outputImage(w, h, os, verifyCode);
		return verifyCode;
	}


	/**
	 * 使用系统默认字符源生成验证码
	 * @param verifySize	验证码长度
	 * @return
	 */
	private static String generateVerifyCode( int verifySize ) {
		int codesLen = VERIFY_CODES.length();
		Random rand = new Random(System.currentTimeMillis());
		StringBuilder verifyCode = new StringBuilder(verifySize);
		for ( int i = 0 ; i < verifySize ; i++ ) {
			int j = rand.nextInt(codesLen);
			//0、随机大小写
			if ( rand.nextBoolean() ) {
				verifyCode.append(VERIFY_CODES.toUpperCase().charAt(j));
			} else {
				verifyCode.append(VERIFY_CODES.charAt(j));
			}
		}
		return verifyCode.toString();
	}


	/**
	 * 生成指定验证码图像文件
	 * @param w
	 * @param h
	 * @param outputFile
	 * @param code
	 * @throws IOException
	 */
	private static void outputImage( int w, int h, File outputFile, String code ) throws IOException {
		if ( outputFile == null ) {
			return;
		}
		File dir = outputFile.getParentFile();
		if ( !dir.exists() ) {
			dir.mkdirs();
		}
		try {
			outputFile.createNewFile();
			FileOutputStream fos = new FileOutputStream(outputFile);
			outputImage(w, h, fos, code);
			fos.close();
		} catch ( IOException e ) {
			throw e;
		}
	}


	/**
	 * 输出指定验证码图片流
	 * @param w
	 * @param h
	 * @param os
	 * @param code
	 * @throws IOException
	 */
	private static void outputImage( int w, int h, OutputStream os, String code ) throws IOException {
		int verifySize = code.length();
		BufferedImage image = new BufferedImage(w, h, BufferedImage.TYPE_INT_RGB);
		Random rand = new Random();
		Graphics2D g2 = image.createGraphics();
		g2.setRenderingHint(RenderingHints.KEY_ANTIALIASING, RenderingHints.VALUE_ANTIALIAS_ON);
		Color[] colors = new Color[5];
		Color[] colorSpaces = new Color[ ] { Color.WHITE, Color.CYAN, Color.GRAY, Color.LIGHT_GRAY, Color.MAGENTA,
				Color.ORANGE, Color.PINK, Color.YELLOW };
		float[] fractions = new float[colors.length];
		for ( int i = 0 ; i < colors.length ; i++ ) {
			colors[i] = colorSpaces[rand.nextInt(colorSpaces.length)];
			fractions[i] = rand.nextFloat();
		}
		Arrays.sort(fractions);

		g2.setColor(Color.GRAY);//设置边框色
		g2.fillRect(0, 0, w, h);

		Color c = getRandColor(200, 250);
		g2.setColor(c);//设置背景色
		g2.fillRect(0, 2, w, h - 4);

		//绘制干扰线
		g2.setColor(getRandColor(160, 200));//设置线条的颜色
		for ( int i = 0 ; i < 20 ; i++ ) {
			int x = random.nextInt(w - 1);
			int y = random.nextInt(h - 1);
			int xl = random.nextInt(6) + 1;
			int yl = random.nextInt(12) + 1;
			g2.drawLine(x, y, x + xl + 40, y + yl + 20);
		}

		//添加噪点
		float yawpRate = 0.05f;//噪声率
		int area = (int) (yawpRate * w * h);
		for ( int i = 0 ; i < area ; i++ ) {
			int x = random.nextInt(w);
			int y = random.nextInt(h);
			int rgb = getRandomIntColor();
			image.setRGB(x, y, rgb);
		}

		shear(g2, w, h, c);//使图片扭曲

		g2.setColor(getRandColor(100, 160));
		int fontSize = h - 4;
		Font font = new Font("Algerian", Font.ITALIC, fontSize);
		g2.setFont(font);
		char[] chars = code.toCharArray();
		for ( int i = 0 ; i < verifySize ; i++ ) {
			AffineTransform affine = new AffineTransform();
			affine.setToRotation(Math.PI / 4 * rand.nextDouble() * (rand.nextBoolean() ? 1 : -1), (w / verifySize)
					* i + fontSize / 2, h / 2);
			g2.setTransform(affine);
			g2.drawChars(chars, i, 1, ((w - 10) / verifySize) * i + 5, h / 2 + fontSize / 2 - 10);
		}

		g2.dispose();
		ImageIO.write(image, "jpg", os);
	}


	private static Color getRandColor( int fc, int bc ) {
		int _fc = 255;
		if ( fc < 255 ) {
			_fc = fc;
		}
		int _bc = 255;
		if ( bc < 255 ) {
			_bc = bc;
		}
		int r = _fc + random.nextInt(_bc - _fc);
		int g = _fc + random.nextInt(_bc - _fc);
		int b = _fc + random.nextInt(_bc - _fc);
		return new Color(r, g, b);
	}


	private static int getRandomIntColor() {
		int[] rgb = getRandomRgb();
		int color = 0;
		for ( int c : rgb ) {
			color = color << 8;
			color = color | c;
		}
		return color;
	}


	private static int[] getRandomRgb() {
		int[] rgb = new int[3];
		for ( int i = 0 ; i < 3 ; i++ ) {
			rgb[i] = random.nextInt(255);
		}
		return rgb;
	}


	private static void shear( Graphics g, int w1, int h1, Color color ) {
		shearX(g, w1, h1, color);
		shearY(g, w1, h1, color);
	}


	private static void shearX( Graphics g, int w1, int h1, Color color ) {
		int period = random.nextInt(2);
		boolean borderGap = true;
		int frames = 1;
		int phase = random.nextInt(2);
		for ( int i = 0 ; i < h1 ; i++ ) {
			double d = (period >> 1) * Math.sin((double) i / (double) period + (6.2831853071795862D * phase) / frames);
			g.copyArea(0, i, w1, 1, (int) d, 0);
			if ( borderGap ) {
				g.setColor(color);
				g.drawLine((int) d, i, 0, i);
				g.drawLine((int) d + w1, i, w1, i);
			}
		}
	}


	private static void shearY( Graphics g, int w1, int h1, Color color ) {
		int period = random.nextInt(40) + 10; // 50;
		boolean borderGap = true;
		int frames = 20;
		int phase = 7;
		for ( int i = 0 ; i < w1 ; i++ ) {
			double d = (period >> 1) * Math.sin((double) i / (double) period + (6.2831853071795862D * phase) / frames);
			g.copyArea(i, 0, 1, h1, 0, (int) d);
			if ( borderGap ) {
				g.setColor(color);
				g.drawLine(i, (int) d, i, 0);
				g.drawLine(i, (int) d + h1, i, h1);
			}
		}
	}


	/**
	 * 测试方法
	 * @param args
	 * @throws IOException
	 */
	public static void main( String[] args ) throws IOException {
		File dir = new File(System.getProperty("user.dir") + "/verifies");
		int w = 200, h = 80;
		for ( int i = 0 ; i < 50 ; i++ ) {
			String verifyCode = generateVerifyCode(4);
			File file = new File(dir, verifyCode + ".jpg");
			outputImage(w, h, file, verifyCode);
		}
	}
}
